There are 3 steps to this happening. Step 1:
Trade for a mediocre PG before the March 15th deadline (The PG listed here will not be the starter next year, just wait):
-- OR --
1B) Lakers get: PG Raymond Felton
Blazers get: PG Steve Blake, 1st or 2nd Round pick (depending how generous lakers are)
Step 2: Trade away Wallace for two reasons: Batum will thrive at SF in the long term and having wallace and batum just doesnt work, you can't loose him to free agency and get nothing in return and you can't sign him because he will ask for way to much to be competing with Nic (honestly, they are truly SFs, dont count either as a SG or PF please). In a trade for wallace get some nice draft picks.
For the remainder of the season, the Blazers probably wont do that great. Oh well...remember this is a long term option that will show success next season and big changes need to happen for this team to be on the incline, not decline.
Step 3: Blazers will have a lot of salary room. SIGN ROY HIBBERT. He is a restricted free agent and also an Eastern Conference All-Star center. This means the Blazers will have to pay a lot for him, but it solves the problem at center and the blazers will have lost Camby because it makes no sense to resign him.
Sign the REAL PG that will start 2012-13 season. Realistically, I'm looking at Steve Nash or Aaron Brooks. D.Will is out of the question because we would have already spent a lot on HIbbert and Williams wouldnt pick Portland. Aaron Brooks just has that Nate McMillan PG look to him. When LA is double-teamed, he can shoot consistently on the perimeter. He was the NBA's most improved player a few years back and one of the leading three point shooters. Plus he cant cost anything more than 6-7 million a year since he has been in China and was only getting paid 2mil with PHX.
Then, keep in mind that there are FA agents at SG... O.J. Mayo, Ray Allen, Jason Terry, etc would all be nice compliments off the bench for a well-equipped team. Maybe trade for a backup SF (someone like Shane Battie, consistent role-player that can play defense). Also keep in mind we should have 1st and 2nd round draft picks that could fill up spaces in the following roster.
Your backup PG is the one traded for in Step 1. Roster would look something like:
PG Brooks (backup plan Nash)
SG Matthews or FA
PG Ridnour or Blake (depending on which trade)
SG Elliot Williams, FA
SF FA, Babbitt
PF Craig Smith
C Pryzbilla, C. Johnson